// extract the result vertices and indices from the GrAAConvexTessellator
static void extract_verts(const GrAAConvexTessellator& tess,
void* vertices,
size_t vertexStride,
GrColor color,
uint16_t firstIndex,
uint16_t* idxs,
bool tweakAlphaForCoverage) {
intptr_t verts = reinterpret_cast<intptr_t>(vertices);
for (int i = 0; i < tess.numPts(); ++i) {
*((SkPoint*)((intptr_t)verts + i * vertexStride)) = tess.point(i);
}
// Make 'verts' point to the colors
verts += sizeof(SkPoint);
for (int i = 0; i < tess.numPts(); ++i) {
if (tweakAlphaForCoverage) {
SkASSERT(SkScalarRoundToInt(255.0f * tess.coverage(i)) <= 255);
unsigned scale = SkScalarRoundToInt(255.0f * tess.coverage(i));
GrColor scaledColor = (0xff == scale) ? color : SkAlphaMulQ(color, scale);
*reinterpret_cast<GrColor*>(verts + i * vertexStride) = scaledColor;
} else {
*reinterpret_cast<GrColor*>(verts + i * vertexStride) = color;
*reinterpret_cast<float*>(verts + i * vertexStride + sizeof(GrColor)) =
tess.coverage(i);
}
}
for (int i = 0; i < tess.numIndices(); ++i) {
idxs[i] = tess.index(i) + firstIndex;
}
}
void prepareLinesOnlyDraws(Target* target) const {
bool canTweakAlphaForCoverage = this->canTweakAlphaForCoverage();
// Setup GrGeometryProcessor
sk_sp<GrGeometryProcessor> gp(create_fill_gp(canTweakAlphaForCoverage,
this->viewMatrix(),
this->usesLocalCoords(),
this->coverageIgnored()));
if (!gp) {
SkDebugf("Could not create GrGeometryProcessor\n");
return;
}
size_t vertexStride = gp->getVertexStride();
SkASSERT(canTweakAlphaForCoverage ?
vertexStride == sizeof(GrDefaultGeoProcFactory::PositionColorAttr) :
vertexStride == sizeof(GrDefaultGeoProcFactory::PositionColorCoverageAttr));
GrAAConvexTessellator tess;
int instanceCount = fGeoData.count();
for (int i = 0; i < instanceCount; i++) {
tess.rewind();
const Geometry& args = fGeoData[i];
if (!tess.tessellate(args.fViewMatrix, args.fPath)) {
continue;
}
const GrBuffer* vertexBuffer;
int firstVertex;
void* verts = target->makeVertexSpace(vertexStride, tess.numPts(), &vertexBuffer,
&firstVertex);
if (!verts) {
SkDebugf("Could not allocate vertices\n");
return;
}
const GrBuffer* indexBuffer;
int firstIndex;
uint16_t* idxs = target->makeIndexSpace(tess.numIndices(), &indexBuffer, &firstIndex);
if (!idxs) {
SkDebugf("Could not allocate indices\n");
return;
}
extract_verts(tess, verts, vertexStride, args.fColor, idxs, canTweakAlphaForCoverage);
GrMesh mesh;
mesh.initIndexed(kTriangles_GrPrimitiveType,
vertexBuffer, indexBuffer,
firstVertex, firstIndex,
tess.numPts(), tess.numIndices());
target->draw(gp.get(), mesh);
}
}
